Answer:
The wavelength of the energy that needs to be absorbed = 52.36 nm
Explanation:
For this study;
Let consider the Rydgberg equation from Bohr's theory of atomic model:
i.e.

where
Z* = effective nuclear charge of atom = Z - σ = 6
n₁ = lower orbit = 3
n₂ = higher orbit = 4
= Rydyberg constant = 1.09 × 10⁷ m⁻¹
λ = wave length of the light absorbed
∴









Therefore, the wavelength of the energy that needs to be absorbed = 52.36 nm
Answer: Empirical formula of this compound is 
Explanation:
Mass of Cr= 104.0 g
Mass of O = 48.0 g
Step 1 : convert given masses into moles.
Moles of Cr =
Moles of O =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Cr = 
For O =
Converting into simple whole number ratios by multiplying by 2
The ratio of Cr : O= 2: 3
Hence the empirical formula is 
The most likely empirical formula of this compound is 
A catalyst increases the reactions rate
Answer:
CuNO3
Explanation:
In order to calculate the empirical formula in this question;
Cu = 50.61% = 50.61g
N = 11.16% = 11.16g
O = 38.23% = 38.23g
Next, we convert each gram unit to moles by dividing by their respective molar mass (Where; Cu = 63.55, N = 14, O = 16)
Cu = 50.61 ÷ 63.55 = 0.796mol
N = 11.16 ÷ 14 = 0.797mol
O = 38.23 ÷ 16 = 2.389mol
Next, we divide each mole value by the smallest (0.796)
Cu = 0.796mol ÷ 0.796 = 1
N = 0.797mol ÷ 0.796 = 1.001
O = 2.389mol ÷ 0.796 = 3.001
Approximately, the simple whole number ratio between Cu, N and O is 1:1:3, hence, the empirical formula is CuNO3.
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